Polysaccharides, especially antigenic polysaccharides, are used in preparation of vaccines. Monovalent, bivalent and poly (multi) valent vaccines containing one, two or more polysaccharides and their conjugates are available in the market for prevention of certain diseases or infections caused by various microorganisms such as Streptococcus pneumoniae, Haemophilus influenzae and N. meningitidis and have proved valuable in preventing the respective diseases to a significant extent. Surveillance data gathered in the years following the introduction of the vaccine Prevenar has clearly demonstrated a reduction of invasive pneumococcal disease in US infants as expected. Despite of several studies carried out on these polysaccharides and conjugates, a need for improving yields as well as quality (purity) of the polysaccharides always exist in the industry as evidenced by the continuing research.
Meningitis is considered as a global threat and the disease burden still remains a public health priority. The clinical definition of meningitis is the inflammation of the meninges (membrane of the brain). If not treated, the disease can have fatal consequences. A total of thirteen serogroups of N. meningitidis have been identified, and out of these thirteen, six serogroups (A, B, C, W135, X and Y) are majorly accountable for causing the infections globally. N. meningitidis has a wide range of clinical manifestations, ranging from transient mild sore throat to fatal meningitis or meningococcal septicemia. Meningitis and septicemia are the most common presentations of the disease.
Evidence collected through numerous research findings defines the immunogenic aspect of the polysaccharide conjugate vaccine. Furthermore, there are research articles as well as patents describing the production and purification of the capsular polysaccharide of Men C but none of them define a purification process with extremely reduced time lines which is robust, scalable, and reproducible.
The production of purified Men C is the foremost requirement for an effective conjugation with the carrier protein and its development as a conjugate vaccine. The cost for the cultivation and the purification of Men C is generally high and involves long working hours as it involves a series of production and purification steps. Improvement in one or more of the steps of polysaccharide production would bring a significant change in the overall conjugate vaccine production and consequently makes the process relatively cost effective.
However, despite of several studies that have been carried out on these polysaccharides, there has always been a need for improving yields as well as quality/purity of the polysaccharides in order to produce vaccines of high quality.
There are a number of patents, which describe the process for the purification of Men-C polysaccharides. The existing state of the art described in U.S. Pat. No. 7,491,517,B2 for precipitating Men-C polysaccharides with CTAB is found to involve overnight incubation at 4° C. Also the removal of contaminants requires the use of costly enzyme Proteinase K. In addition to this, the process also requires gel filtration for the purification of the Men-C polysaccharides. The overall procedure requires significant time for purification and also the process becomes costly because of the use of enzymes.
Also, the Application No. WO 2011/148382 A1 describes the method of preparing pure capsular polysaccharide using aluminium phosphate with alcohol for the purification of capsular polysaccharides of Haemophilus influenzae b, N. meningitidis such as serogroups A, C, Y, W-135 and other similar capsular polysaccharides produced form both gram negative and gram positive microorganisms. The said published prior art discloses a time of 16-20 hrs for the purification of the polysaccharides.
Another patent EP 0658118B1 describes a method for O-Deacetylation of Group C Meningococcal Polysaccharide (GCMP) with an average time of 16 hours. This process also requires significant time for purification
Presently, the various methods used for the production and purification of MenC polysaccharides takes relatively long cultivation and purification time and also involves the use of costly enzymes. Though these kinds of processes give pure polysaccharides but they will concurrently increase the cost of production during scale-up.
Furthermore the above disclosed prior arts teach methods which are more efficient at low temperature thereby requiring a controlled environment leading to addition of costs in research and production.